1. Field of the Invention
The present disclosure relates to cold spray systems, and more particularly to powder feedstock manufacturing for cold spray systems.
2. Description of Related Art
Cold spray processes are used to develop coatings on target substrates. The coatings can be thin or thick, and form protective or performance enhancing layers on the substrate. The layers can also repair damage to the underlying substrate. The coatings can be formed from materials such as aluminum, copper, iron, or nickel. The coatings can also be formed from high strength alloys, such as Inconel® for example.
Cold spray processes form coatings by propelling powder feedstock particles to extremely high speeds by a carrier gas through a nozzle oriented toward a target substrate. The particles impact the substrate with sufficient kinetic energy to deform plastically and bond with the substrate, thereby forming a coating on the substrate. Cold spray is distinguishable from other spray deposition processes that melt the feedstock particles prior to propelling the particles toward the substrate, such as thermal and plasma spray processes. In contrast, cold spray processes typically do not change the physical state or chemical composition of the feedstock particles between their introduction into the system and their application to the substrate.
Not changing the state or chemistry of the feedstock particles has advantages and disadvantages. Since the chemical composition of the feedstock particles generally does not change introduction of the powder feedstock into the cold spray system and application to the substrate, coatings developed by cold spray processes generally have the same composition the powder feedstock material introduced to the cold spray system. For this same reasons, however, impurities or contaminates in powder feedstock introduced to the cold spray system can be incorporated into the coating developed on the substrate. This can pose challenges to cold spray processes using powder feedstock materials tending to form oxides or hydroxides when exposed to the ambient environment, like aluminum for example, as the oxides and hydroxides can change the coating composition, potentially altering the coating performance.
Conventional cold spray systems and methods have generally been considered satisfactory for their intended purpose. However, there is a need in the art for improved systems and methods for generating powder feedstock for cold spray systems. The present disclosure provides a solution for these problems.